fs/ocfs2/acl.c

   1 /* -*- mode: c; c-basic-offset: 8; -*-
   2  * vim: noexpandtab sw=8 ts=8 sts=0:
   3  *
   4  * acl.c
   5  *
   6  * Copyright (C) 2004, 2008 Oracle.  All rights reserved.
   7  *
   8  * CREDITS:
   9  * Lots of code in this file is copy from linux/fs/ext3/acl.c.
  10  * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public
  14  * License version 2 as published by the Free Software Foundation.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19  * General Public License for more details.
  20  */
  21
  22 #include <linux/init.h>
  23 #include <linux/module.h>
  24 #include <linux/slab.h>
  25 #include <linux/string.h>
  26
  27 #include <cluster/masklog.h>
  28
  29 #include "ocfs2.h"
  30 #include "alloc.h"
  31 #include "dlmglue.h"
  32 #include "file.h"
  33 #include "inode.h"
  34 #include "journal.h"
  35 #include "ocfs2_fs.h"
  36
  37 #include "xattr.h"
  38 #include "acl.h"
  39
  40 /*
  41  * Convert from xattr value to acl struct.
  42  */
  43 static struct posix_acl *ocfs2_acl_from_xattr(const void *value, size_t size)
  44 {
  45         int n, count;
  46         struct posix_acl *acl;
  47
  48         if (!value)
  49                 return NULL;
  50         if (size < sizeof(struct posix_acl_entry))
  51                 return ERR_PTR(-EINVAL);
  52
  53         count = size / sizeof(struct posix_acl_entry);
  54         if (count < 0)
  55                 return ERR_PTR(-EINVAL);
  56         if (count == 0)
  57                 return NULL;
  58
  59         acl = posix_acl_alloc(count, GFP_NOFS);
  60         if (!acl)
  61                 return ERR_PTR(-ENOMEM);
  62         for (n = 0; n < count; n++) {
  63                 struct ocfs2_acl_entry *entry =
  64                         (struct ocfs2_acl_entry *)value;
  65
  66                 acl->a_entries[n].e_tag  = le16_to_cpu(entry->e_tag);
  67                 acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);
  68                 acl->a_entries[n].e_id   = le32_to_cpu(entry->e_id);
  69                 value += sizeof(struct posix_acl_entry);
  70
  71         }
  72         return acl;
  73 }
  74
  75 /*
  76  * Convert acl struct to xattr value.
  77  */
  78 static void *ocfs2_acl_to_xattr(const struct posix_acl *acl, size_t *size)
  79 {
  80         struct ocfs2_acl_entry *entry = NULL;
  81         char *ocfs2_acl;
  82         size_t n;
  83
  84         *size = acl->a_count * sizeof(struct posix_acl_entry);
  85
  86         ocfs2_acl = kmalloc(*size, GFP_NOFS);
  87         if (!ocfs2_acl)
  88                 return ERR_PTR(-ENOMEM);
  89
  90         entry = (struct ocfs2_acl_entry *)ocfs2_acl;
  91         for (n = 0; n < acl->a_count; n++, entry++) {
  92                 entry->e_tag  = cpu_to_le16(acl->a_entries[n].e_tag);
  93                 entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm);
  94                 entry->e_id   = cpu_to_le32(acl->a_entries[n].e_id);
  95         }
  96         return ocfs2_acl;
  97 }
  98
  99 static struct posix_acl *ocfs2_get_acl_nolock(struct inode *inode,
 100                                               int type,
 101                                               struct buffer_head *di_bh)
 102 {
 103         int name_index;
 104         char *value = NULL;
 105         struct posix_acl *acl;
 106         int retval;
 107
 108         switch (type) {
 109         case ACL_TYPE_ACCESS:
 110                 name_index = OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS;
 111                 break;
 112         case ACL_TYPE_DEFAULT:
 113                 name_index = OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT;
 114                 break;
 115         default:
 116                 return ERR_PTR(-EINVAL);
 117         }
 118
 119         retval = ocfs2_xattr_get_nolock(inode, di_bh, name_index, "", NULL, 0);
 120         if (retval > 0) {
 121                 value = kmalloc(retval, GFP_NOFS);
 122                 if (!value)
 123                         return ERR_PTR(-ENOMEM);
 124                 retval = ocfs2_xattr_get_nolock(inode, di_bh, name_index,
 125                                                 "", value, retval);
 126         }
 127
 128         if (retval > 0)
 129                 acl = ocfs2_acl_from_xattr(value, retval);
 130         else if (retval == -ENODATA || retval == 0)
 131                 acl = NULL;
 132         else
 133                 acl = ERR_PTR(retval);
 134
 135         kfree(value);
 136
 137         return acl;
 138 }
 139
 140
 141 /*
 142  * Get posix acl.
 143  */
 144 static struct posix_acl *ocfs2_get_acl(struct inode *inode, int type)
 145 {
 146         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 147         struct buffer_head *di_bh = NULL;
 148         struct posix_acl *acl;
 149         int ret;
 150
 151         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 152                 return NULL;
 153
 154         ret = ocfs2_inode_lock(inode, &di_bh, 0);
 155         if (ret < 0) {
 156                 mlog_errno(ret);
 157                 acl = ERR_PTR(ret);
 158                 return acl;
 159         }
 160
 161         acl = ocfs2_get_acl_nolock(inode, type, di_bh);
 162
 163         ocfs2_inode_unlock(inode, 0);
 164
 165         brelse(di_bh);
 166
 167         return acl;
 168 }
 169
 170 /*
 171  * Helper function to set i_mode in memory and disk. Some call paths
 172  * will not have di_bh or a journal handle to pass, in which case it
 173  * will create it's own.
 174  */
 175 static int ocfs2_acl_set_mode(struct inode *inode, struct buffer_head *di_bh,
 176                               handle_t *handle, umode_t new_mode)
 177 {
 178         int ret, commit_handle = 0;
 179         struct ocfs2_dinode *di;
 180
 181         if (di_bh == NULL) {
 182                 ret = ocfs2_read_inode_block(inode, &di_bh);
 183                 if (ret) {
 184                         mlog_errno(ret);
 185                         goto out;
 186                 }
 187         } else
 188                 get_bh(di_bh);
 189
 190         if (handle == NULL) {
 191                 handle = ocfs2_start_trans(OCFS2_SB(inode->i_sb),
 192                                            OCFS2_INODE_UPDATE_CREDITS);
 193                 if (IS_ERR(handle)) {
 194                         ret = PTR_ERR(handle);
 195                         mlog_errno(ret);
 196                         goto out_brelse;
 197                 }
 198
 199                 commit_handle = 1;
 200         }
 201
 202         di = (struct ocfs2_dinode *)di_bh->b_data;
 203         ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
 204                                       OCFS2_JOURNAL_ACCESS_WRITE);
 205         if (ret) {
 206                 mlog_errno(ret);
 207                 goto out_commit;
 208         }
 209
 210         inode->i_mode = new_mode;
 211         inode->i_ctime = CURRENT_TIME;
 212         di->i_mode = cpu_to_le16(inode->i_mode);
 213         di->i_ctime = cpu_to_le64(inode->i_ctime.tv_sec);
 214         di->i_ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
 215
 216         ocfs2_journal_dirty(handle, di_bh);
 217
 218 out_commit:
 219         if (commit_handle)
 220                 ocfs2_commit_trans(OCFS2_SB(inode->i_sb), handle);
 221 out_brelse:
 222         brelse(di_bh);
 223 out:
 224         return ret;
 225 }
 226
 227 /*
 228  * Set the access or default ACL of an inode.
 229  */
 230 static int ocfs2_set_acl(handle_t *handle,
 231                          struct inode *inode,
 232                          struct buffer_head *di_bh,
 233                          int type,
 234                          struct posix_acl *acl,
 235                          struct ocfs2_alloc_context *meta_ac,
 236                          struct ocfs2_alloc_context *data_ac)
 237 {
 238         int name_index;
 239         void *value = NULL;
 240         size_t size = 0;
 241         int ret;
 242
 243         if (S_ISLNK(inode->i_mode))
 244                 return -EOPNOTSUPP;
 245
 246         switch (type) {
 247         case ACL_TYPE_ACCESS:
 248                 name_index = OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS;
 249                 if (acl) {
 250                         mode_t mode = inode->i_mode;
 251                         ret = posix_acl_equiv_mode(acl, &mode);
 252                         if (ret < 0)
 253                                 return ret;
 254                         else {
 255                                 if (ret == 0)
 256                                         acl = NULL;
 257
 258                                 ret = ocfs2_acl_set_mode(inode, di_bh,
 259                                                          handle, mode);
 260                                 if (ret)
 261                                         return ret;
 262
 263                         }
 264                 }
 265                 break;
 266         case ACL_TYPE_DEFAULT:
 267                 name_index = OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT;
 268                 if (!S_ISDIR(inode->i_mode))
 269                         return acl ? -EACCES : 0;
 270                 break;
 271         default:
 272                 return -EINVAL;
 273         }
 274
 275         if (acl) {
 276                 value = ocfs2_acl_to_xattr(acl, &size);
 277                 if (IS_ERR(value))
 278                         return (int)PTR_ERR(value);
 279         }
 280
 281         if (handle)
 282                 ret = ocfs2_xattr_set_handle(handle, inode, di_bh, name_index,
 283                                              "", value, size, 0,
 284                                              meta_ac, data_ac);
 285         else
 286                 ret = ocfs2_xattr_set(inode, name_index, "", value, size, 0);
 287
 288         kfree(value);
 289
 290         return ret;
 291 }
 292
 293 int ocfs2_check_acl(struct inode *inode, int mask, unsigned int flags)
 294 {
 295         struct ocfs2_super *osb;
 296         struct buffer_head *di_bh = NULL;
 297         struct posix_acl *acl;
 298         int ret = -EAGAIN;
 299
 300         if (flags & IPERM_FLAG_RCU)
 301                 return -ECHILD;
 302
 303         osb = OCFS2_SB(inode->i_sb);
 304         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 305                 return ret;
 306
 307         ret = ocfs2_read_inode_block(inode, &di_bh);
 308         if (ret < 0) {
 309                 mlog_errno(ret);
 310                 return ret;
 311         }
 312
 313         acl = ocfs2_get_acl_nolock(inode, ACL_TYPE_ACCESS, di_bh);
 314
 315         brelse(di_bh);
 316
 317         if (IS_ERR(acl)) {
 318                 mlog_errno(PTR_ERR(acl));
 319                 return PTR_ERR(acl);
 320         }
 321         if (acl) {
 322                 ret = posix_acl_permission(inode, acl, mask);
 323                 posix_acl_release(acl);
 324                 return ret;
 325         }
 326
 327         return -EAGAIN;
 328 }
 329
 330 int ocfs2_acl_chmod(struct inode *inode)
 331 {
 332         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 333         struct posix_acl *acl, *clone;
 334         int ret;
 335
 336         if (S_ISLNK(inode->i_mode))
 337                 return -EOPNOTSUPP;
 338
 339         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 340                 return 0;
 341
 342         acl = ocfs2_get_acl(inode, ACL_TYPE_ACCESS);
 343         if (IS_ERR(acl) || !acl)
 344                 return PTR_ERR(acl);
 345         clone = posix_acl_clone(acl, GFP_KERNEL);
 346         posix_acl_release(acl);
 347         if (!clone)
 348                 return -ENOMEM;
 349         ret = posix_acl_chmod_masq(clone, inode->i_mode);
 350         if (!ret)
 351                 ret = ocfs2_set_acl(NULL, inode, NULL, ACL_TYPE_ACCESS,
 352                                     clone, NULL, NULL);
 353         posix_acl_release(clone);
 354         return ret;
 355 }
 356
 357 /*
 358  * Initialize the ACLs of a new inode. If parent directory has default ACL,
 359  * then clone to new inode. Called from ocfs2_mknod.
 360  */
 361 int ocfs2_init_acl(handle_t *handle,
 362                    struct inode *inode,
 363                    struct inode *dir,
 364                    struct buffer_head *di_bh,
 365                    struct buffer_head *dir_bh,
 366                    struct ocfs2_alloc_context *meta_ac,
 367                    struct ocfs2_alloc_context *data_ac)
 368 {
 369         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 370         struct posix_acl *acl = NULL;
 371         int ret = 0, ret2;
 372         mode_t mode;
 373
 374         if (!S_ISLNK(inode->i_mode)) {
 375                 if (osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) {
 376                         acl = ocfs2_get_acl_nolock(dir, ACL_TYPE_DEFAULT,
 377                                                    dir_bh);
 378                         if (IS_ERR(acl))
 379                                 return PTR_ERR(acl);
 380                 }
 381                 if (!acl) {
 382                         mode = inode->i_mode & ~current_umask();
 383                         ret = ocfs2_acl_set_mode(inode, di_bh, handle, mode);
 384                         if (ret) {
 385                                 mlog_errno(ret);
 386                                 goto cleanup;
 387                         }
 388                 }
 389         }
 390         if ((osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) && acl) {
 391                 struct posix_acl *clone;
 392
 393                 if (S_ISDIR(inode->i_mode)) {
 394                         ret = ocfs2_set_acl(handle, inode, di_bh,
 395                                             ACL_TYPE_DEFAULT, acl,
 396                                             meta_ac, data_ac);
 397                         if (ret)
 398                                 goto cleanup;
 399                 }
 400                 clone = posix_acl_clone(acl, GFP_NOFS);
 401                 ret = -ENOMEM;
 402                 if (!clone)
 403                         goto cleanup;
 404
 405                 mode = inode->i_mode;
 406                 ret = posix_acl_create_masq(clone, &mode);
 407                 if (ret >= 0) {
 408                         ret2 = ocfs2_acl_set_mode(inode, di_bh, handle, mode);
 409                         if (ret2) {
 410                                 mlog_errno(ret2);
 411                                 ret = ret2;
 412                                 goto cleanup;
 413                         }
 414                         if (ret > 0) {
 415                                 ret = ocfs2_set_acl(handle, inode,
 416                                                     di_bh, ACL_TYPE_ACCESS,
 417                                                     clone, meta_ac, data_ac);
 418                         }
 419                 }
 420                 posix_acl_release(clone);
 421         }
 422 cleanup:
 423         posix_acl_release(acl);
 424         return ret;
 425 }
 426
 427 static size_t ocfs2_xattr_list_acl_access(struct dentry *dentry,
 428                                           char *list,
 429                                           size_t list_len,
 430                                           const char *name,
 431                                           size_t name_len,
 432                                           int type)
 433 {
 434         struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
 435         const size_t size = sizeof(POSIX_ACL_XATTR_ACCESS);
 436
 437         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 438                 return 0;
 439
 440         if (list && size <= list_len)
 441                 memcpy(list, POSIX_ACL_XATTR_ACCESS, size);
 442         return size;
 443 }
 444
 445 static size_t ocfs2_xattr_list_acl_default(struct dentry *dentry,
 446                                            char *list,
 447                                            size_t list_len,
 448                                            const char *name,
 449                                            size_t name_len,
 450                                            int type)
 451 {
 452         struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
 453         const size_t size = sizeof(POSIX_ACL_XATTR_DEFAULT);
 454
 455         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 456                 return 0;
 457
 458         if (list && size <= list_len)
 459                 memcpy(list, POSIX_ACL_XATTR_DEFAULT, size);
 460         return size;
 461 }
 462
 463 static int ocfs2_xattr_get_acl(struct dentry *dentry, const char *name,
 464                 void *buffer, size_t size, int type)
 465 {
 466         struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
 467         struct posix_acl *acl;
 468         int ret;
 469
 470         if (strcmp(name, "") != 0)
 471                 return -EINVAL;
 472         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 473                 return -EOPNOTSUPP;
 474
 475         acl = ocfs2_get_acl(dentry->d_inode, type);
 476         if (IS_ERR(acl))
 477                 return PTR_ERR(acl);
 478         if (acl == NULL)
 479                 return -ENODATA;
 480         ret = posix_acl_to_xattr(acl, buffer, size);
 481         posix_acl_release(acl);
 482
 483         return ret;
 484 }
 485
 486 static int ocfs2_xattr_set_acl(struct dentry *dentry, const char *name,
 487                 const void *value, size_t size, int flags, int type)
 488 {
 489         struct inode *inode = dentry->d_inode;
 490         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 491         struct posix_acl *acl;
 492         int ret = 0;
 493
 494         if (strcmp(name, "") != 0)
 495                 return -EINVAL;
 496         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 497                 return -EOPNOTSUPP;
 498
 499         if (!inode_owner_or_capable(inode))
 500                 return -EPERM;
 501
 502         if (value) {
 503                 acl = posix_acl_from_xattr(value, size);
 504                 if (IS_ERR(acl))
 505                         return PTR_ERR(acl);
 506                 else if (acl) {
 507                         ret = posix_acl_valid(acl);
 508                         if (ret)
 509                                 goto cleanup;
 510                 }
 511         } else
 512                 acl = NULL;
 513
 514         ret = ocfs2_set_acl(NULL, inode, NULL, type, acl, NULL, NULL);
 515
 516 cleanup:
 517         posix_acl_release(acl);
 518         return ret;
 519 }
 520
 521 const struct xattr_handler ocfs2_xattr_acl_access_handler = {
 522         .prefix = POSIX_ACL_XATTR_ACCESS,
 523         .flags  = ACL_TYPE_ACCESS,
 524         .list   = ocfs2_xattr_list_acl_access,
 525         .get    = ocfs2_xattr_get_acl,
 526         .set    = ocfs2_xattr_set_acl,
 527 };
 528
 529 const struct xattr_handler ocfs2_xattr_acl_default_handler = {
 530         .prefix = POSIX_ACL_XATTR_DEFAULT,
 531         .flags  = ACL_TYPE_DEFAULT,
 532         .list   = ocfs2_xattr_list_acl_default,
 533         .get    = ocfs2_xattr_get_acl,
 534         .set    = ocfs2_xattr_set_acl,
 535 };